This preprint was accepted September 2, 2000
Contact:
S.V.Buyalo
ABSTRACT: A graph surface $P$ is a 2-dimensional polyhedron having a simplest kind of nontrivial singularities which result from gluing surfaces with compact boundaries along boundary components. We study the behavior of the volume entropy $h(g)$ of hyperbolic metrics $g$ on a closed graph surface $P$ depending on the lenghts of singular geodesics $Q\sub P$. We show that always $h(g)>1$ and $h(g)\to\infty$ as $L_g(Q)\to\infty$ for at least one singular geodesic $Q$.[ Full text: (.ps.gz)]